The safe body and door are constructed with double-wall, heavy-gauge cold-rolled steel filled with a specialized, ultra-dense composite fire-insulating slurry. Engineered to maintain safe internal temperatures during high-heat fires, the structure preserves paper documentation and critical media through extreme thermal events. The outer frame is coated in an electrostatic powder-coated finish, offering superior resistance against rust, scratches, and chemical cleaners. A heat-expanding intumescent door seal automatically swells during extreme heat exposure to completely block smoke, hot gases, and water ingress from firefighting equipment.